Helivue Design 17 Gallon Auxiliary Fuel Tank System install/review

[rommelrommel]

This is a new option for GX470 owners to the LRA tank. They did a pre-sale and I was one of the 20. It was 1200 USD+ shipping, cost to go up after this batch.

It’s an aluminum tank with 17 gallons capacity.

First off, packing was okay. I think it needs more internal packing because you can’t count on the couriers to not beat up parcels. But, it’s a heck of a lot lighter than the LRA and can be shipped in a box.

Tank itself looks well made

All parts listed were present.

First thing I worked on was wiring. I lost some of the pictures somehow, but it’s quite simple. There’s a switch that looks like it’s probably the same as LRA. It has a controller box it connects to via a harness. Then you just need power and ground, and then there’s a shielded pair of wires that goes to the tank area. I took power and ground from under the hood at my blue sea fuse block.

Mounting the switch was pretty easy, I used a 3/4 spade bit to punch a hole in one of my 3d printed switch panels and then did final enlarging with a round file. I should have put it about 2mm higher but it’s fine.

I’ll post more as I go. I ordered a used fuel filler neck to do the mods to, that way I can both have a spare if I ever have to reverse it, and I can get help with the welding and be prepared to do the final install in one shot.

 

[rommelrommel]

Well, I discovered that the KDSS filler neck is actually different from the regular one. It's bent a bit different to accommodate the KDSS ram. This wiped out all my prep work on the spare filler and made this semi-irreversible until I track down a KDSS filler neck. I also ran into some problems with the length of certain lines and ended up running out to buy more of all three sized fuel lines.

So downside... despite having ran the wiring most of the way, done the rivnuts, prepped as much of the tank as I could, etc on previous evenings when I had a bit of time I easily spent another 6 hours today and only got it all connected (I think.) Truck started and ran for a while with no evap codes. Switch lit up and showed the tank empty. My take on this so far is you better be moderately good turning a wrench and mostly be very patient and willing to fit things up, adjust, fit some more, adjust, etc. With KDSS and air suspension still there it is very crowded around the KDSS ram, air tank, evap stuff, and T fittings for fuel and rollover lines.

 

[rommelrommel]

Catch up on some of the previous stuff.

This is what I did to the bottom of my ACC Becky tire carrier support. It conflicts with the tank so any additional flex that comes with I’ll just have to live with.

Drilling out the fuel filler

I used a step drill and took it to 1/2”. Then I used the fitting to thread it a little so it would naturally have some strength.

I showed this to my millwright buddy asking if he thought welding was a good idea. Said he could do it but suggested just using permatex #2. I did a little research and decided to use a fuel tank repair epoxy for a little extra strength.

Roughed up the area good for adherence and after it dried painted it.

 

[rommelrommel]

Fuel pump I put more or less where they suggested but here I ran into the first issue with the provided fuel line. It’s cut so exactly that you must put the pump exactly where they did to make it work. I cut a new piece between the pump and the filler T so I could easily connect everything without tension. Instead of using the provided self tappers I drilled and then tapped the frame for m6 holes.

Skipping a bit of stuff here due to not taking enough pictures, but here’s fuel line problem number 2. I think this is due to the KDSS fuel filler, but the pipe is about an inch short of really making good contact on both ends of the pipe. I went out and bought more to cut a new piece. In the end I also cut a new piece of the short 2” couplers for the main filler line ends, as it gave me some room to make sure the clamps were gripping well where I made the final connection between the filler neck to inlet portion. The final thing I adjusted with was the rollover line T connection. The kit has just enough fuel line to connect the t fitting to the main line, but when trying to get everything together it’s a mess to have everything needing to line up and be worked on at once. I cut out more of the hard line so I could replace it with fuel line to give me the ability to hook it up separately easily.

I will get some more pics of my final solution tomorrow hopefully.

 

[Jstawgn]

I haven't got the install completed yet too. Got to go to an event last week and got to move my daughter this week.
Run my electronic thru the air compressor body grommet.

Also did a leak check using simple contraption and AN8 caps. Used soapy water to find any leak. Found a little leak around the fuel sender. Tighten the screw a bit and the leak stopped.

Planning to keep that shutoff valve to be able to prevent filling aux tank when not needed.

Need to cut my filler neck and weld the bung on. That permatex fuel tank repair stuff is interesting idea.

Where did you relocate the charcoal canister filter? Did not see it in your pictures. I don't have any air suspension components anymore and hopefully got less issue.

 

[rommelrommel]

Right now the little charcoal box is not bolted down, the KDSS fuel filler neck line for that ends up pointing right at the hose between the tank and T connection. I removed the metal clamp that holds the three lines together to get enough play to move the vent line a bit. I did try bending it but the line is very strong and without a pipe bending setup available I was afraid to bust it. I'll get some pics.

Nice idea on leak testing. I'll get some pics today and post, basically I hope I don't have issues but I'm more worried about all the clamps on lines. I also did a quick and dirty paint job, so just to slow down on corrosion and also not draw attention to it, we do get gas tanks occasionally drilled to steal fuel.

 

[rommelrommel]

Showing how close you get to the evap box.

Fuel pump mounting. I have a Coastal Off-road bumper.

Mostly final config. My solution was to use a longer bolt to tuck the charcoal canister up even higher than the bracket allows. I also removed the clamp that holds the three hard lines together to get some play in the line that goes to the charcoal canister, because where it was to begin with was pointed right at the filler line for the aux tank. Whether I went over or under it the line got pinched completely shut.

Wider picture of how crowded it starts to get.

Vent tube running up to the filler neck.

 

[rommelrommel]

Have driven around for about an hour, no evap leaks, no visible leaks. No weird rattles, don't notice the weight.

The gauge freaked me out a bit momentarily, when you start the truck with it full it takes a while to work up from one light to all five. It's one light every 20 seconds or something.

Only remaining test is the transfer pump, once I run it down about a half tank I will test that.

 

[rommelrommel]

View of how low the tank hangs with the coastal off-road bumper. This bumper is bolted right to the bottom of the frame so short of the weld in crossmember replacements it’s as far off the ground as possible.

Side view

My body mounts are original, it's possible that with new ones would have this barely hang down at all.

 

[Jstawgn]

Tried welding the filler neck and it's really difficult. Tested using my trusty ryobi air mattress compressor and soapy water and found a few pinholes. I gave up and would use same method like you. Cannot find permatex locally. End up using JB weld tank repair.

 

[rommelrommel]

Still working fine, although haven’t driven much.

Last couple things I was waiting for this to do, mudflaps and permanently mounting the 7 pin wiring.

Cutting the coastal bumper and the factory crossmember with a hole saw wasn’t exactly fun, but I got it done. Mudflaps are three bolts and can be taken off for harder core rocks or whatever.

 

[Jstawgn]

First drive today. No check engine light so far. Hopefully everything is leak free. Haven't filled it with gas yet. I am going to wait for a few days. Incase I need to drop the tank again. The aluminum tank is really light. No need for a jack or anything. One hand hold the tank and the other instal the bolt.

I stil have to find a place for tow harness. Temporarily mounted and it definitely leaving the chat on first steep obstacle. Don't know what to do yet.

 

[rommelrommel]

First drive today. No check engine light so far. Hopefully everything is leak free. Haven't filled it with gas yet. I am going to wait for a few days. Incase I need to drop the tank again. The aluminum tank is really light. No need for a jack or anything. One hand hold the tank and the other instal the bolt.

I stil have to find a place for tow harness. Temporarily mounted and it definitely leaving the chat on first steep obstacle. Don't know what to do yet.
View attachment 3693279

Did you have any of the issues I had? I talked to Joe and he has an 2006 with KDSS just like me and the charcoal canister wasn’t a problem for him.

 

[Jstawgn]

Did you have any of the issues I had? I talked to Joe and he has an 2006 with KDSS just like me and the charcoal canister wasn’t a problem for him.

No issue. I don't have air suspension anymore and looking at your install the air tank might be causing all your trouble. I don't even need to drill and tap for the pump. The abandoned bolt holes from the removed air tank is used for it.

 

[rommelrommel]

So I’m on my second full fill, and the first time I thought I bumped the transfer switch by accident after about 100 miles because my main gauge stayed close to full but the aux tank worked itself to 3 lights.

Now the same thing is happening again, so I’m convinced that driving around is transferring fuel into the main tank by sloshing up the filler neck. My driveway is 400 yards long and steep, and I go up/down some pretty good grades on my way to and from work. I’m actually pretty good with this, the pump is a bit loud and using it less works for me.

 

[HomersCanyonero]

nice reporting on your installs of the 17 gal tanks

What are the advantages of this 17 gal tank over the larger ones?

 

[rommelrommel]

Lighter
Works out of the box with 6500lb hitch
Works out of the box with KDSS
Cheaper
Ships in a box to your house instead of going freight on a pallet (significant savings depending how far away you are from the vendor)
Doesn’t hang as low I think

Cons would be less capacity
Tank is aluminium so weaker if it takes a hit
Less proven/unknown long term support
No baffles (although I have noticed no sloshing)

 

[Jstawgn]

So I’m on my second full fill, and the first time I thought I bumped the transfer switch by accident after about 100 miles because my main gauge stayed close to full but the aux tank worked itself to 3 lights.

Now the same thing is happening again, so I’m convinced that driving around is transferring fuel into the main tank by sloshing up the filler neck. My driveway is 400 yards long and steep, and I go up/down some pretty good grades on my way to and from work. I’m actually pretty good with this, the pump is a bit loud and using it less works for me.

Yep, my main gas tank gauge stays full for 145 miles. I was so happy thinking it change my GX to have prius fuel economy for a bit

This is a known issue with LRA too.
OEM tank have a flap door that keep the fuel inside the tank. There is a aftermarket valve available but not in the correct size.

PERKO Inc. - Catalog - Fuel System Components - Special Application Inlet Check Valves - Flapper Valve [0635]

PERKO Figure No. 0635 Special Application Inlet Check Valves - Flapper Valve [0635000, 0635DP0, 0635DP2, 0635002]

www.perko.com

Perko also makes a valve that would isolate fuel from getting into the vent lines. If we have this vent valve installed, the vent does not need to go to filler neck. Technically It can be tied to the OEM tank vent lines in front of charcoal canister.

This tank technically are built more like a boat fuel tank instead of car fuel tank.

 

[GXFamily]

I wonder how that thing will hold up in a rear end collision.

Big safety concern, possibly?

 

[rommelrommel]

Well, they put a fuel tank back there in other markets. Could it rupture, sure it could if you're hit hard enough.